Price does not follow mining activity, the activity follows the price in the long term. One diff adjustment is simply not enough to say that we will go to the moon.
There is a valid argument that even this may be incorrect to a certain extent if you take a look at the hash rate chart from Dec 2017, all the way to today's date, it's a an exact inverted image of the price chart, in other words, price kept going down for months while difficulty kept going up.
It has to do with many factors, gear efficiency, more gamblers entering the game, newbies have no clue about anything and they keep adding more gears to the network, some might even might at loss in the hope for
BTC price to go up "which is not the best thing to do IMO", there are many other reasons why mining activities can be almost completely independent of price.